Channel encryption unit KCG-70; manufactured by Gretag together with Brown Boveri.

The KCG-70 channel encryption unit allows the encryption of analogue voice or data communication via telephone and radio relay connections and also the recording and playback of encrypted messages using a tape recorder.

• Principle: Digital ciphering system
• Operation modes: Voice encryption, analogue data, digital data
• Frequency range: 300 - 3000 Hz (voice), 300 - 2250 Hz (data)

• Mains operation: nominal 220 (187 - 253) volts AC
• Batteries: nominal 24 (20 - 37) volts DC

• Basic unit: 604 x 385 x 285 mm, 39 kg
• Accessories case: 604 x 385 x 285 mm, 28 kg

The KCG-70 channel encryption unit is used for the encryption of analogue voice or data communication via telephone and radio relay connections and also the recording and playback of encrypted messages via a tape recorder.

With the KCG-70, encrypted voice or data communication is possible via one or two opposing (duplex) channels, transmission can be by wire, microwave relay or a radio system with high transmission quality (FM); storage and retrieval of content from a tape recorder is also possible.

The KCG-70 consists of a basic unit with a modular design and a control unit (BEDI), which can be operated remotely via a cable up to a maximum distance of 30 metres.

It can be used on lines between ATf-53, LB-53 or PTT model 50 telephones, on microwave relay links, for example with R-902 and with restrictions via FM radio connections; short-wave radio connections are not suitable due to transmission failures (fading, etc.).

The KCG-70 can also encrypt lines with analogue or digital data traffic (CCITT V.24).

Simplex or semi-duplex traffic can be used on two-wire lines or wireless connections (as with radio traffic, you must switch between „transmit“ and „receive“ using a push-to-talk button or on the control unit; a four-wire line is required for full duplex operation.

The KCG-70 is fully solid state.

The KCG-70 was developed by the crypto company Gretag (Dr Gretener AG) together with Brown Boveri.

• channel-ciphering-device KCG-70